initial commitHEADmaster

1 files changed, 99 insertions, 0 deletions

diff --git a/src/copybtn.js b/src/copybtn.js
new file mode 100644
index 0000000..869e318
--- /dev/null
+++ b/src/copybtn.js
@@ -0,0 +1,99 @@
+/* Manage "Copy Buttons" linked to target elements, to copy the text (or, parts
+** thereof) of the target elements to the clipboard.
+**
+** Newly created buttons are <button> elements plus a nested <span> element with
+** an SVG background icon, defined by the "copy-button" class in the default CSS
+** style sheet, and are assigned the element ID "copy-<idTarget>".
+**
+** For HTML-defined buttons, either initCopyButtonById(), or initCopyButton(),
+** needs to be called to attach the "onclick" handler (done automatically from
+** a handler attached to the "DOMContentLoaded" event). These functions create
+** the nested <span> element if the <button> element has no child nodes. Using
+** static HTML for the <span> element ensures the buttons are visible if there
+** are script errors, which may be useful for Fossil JS hackers (as good parts
+** of the Fossil web UI come down on JS errors, anyway).
+**
+** The initialization functions do not overwrite the "data-copytarget" and
+** "data-copylength" attributes with empty or null values for <idTarget> and
+** <cchLength>, respectively. Set <cchLength> to "-1" to explicitly remove the
+** previous copy length limit.
+**
+** HTML snippet for statically created buttons:
+**
+**    <button
+**       class="copy-button"
+**       id="copy-<idTarget>"
+**       data-copytarget="<idTarget>"
+**       data-copylength="<cchLength>"
+**       data-content="<content>">
+**       <span></span>
+**    </button>
+*/
+function makeCopyButton(idTarget,bFlipped,cchLength){
+  var elButton = document.createElement("button");
+  elButton.className = "copy-button";
+  if( bFlipped ) elButton.className += " copy-button-flipped";
+  elButton.id = "copy-" + idTarget;
+  initCopyButton(elButton,idTarget,cchLength);
+  return elButton;
+}
+function initCopyButtonById(idButton,idTarget,cchLength){
+  idButton = idButton || "copy-" + idTarget;
+  var elButton = document.getElementById(idButton);
+  if( elButton ) initCopyButton(elButton,idTarget,cchLength);
+  return elButton;
+}
+function initCopyButton(elButton,idTarget,cchLength){
+  if( idTarget ) elButton.setAttribute("data-copytarget",idTarget);
+  if( cchLength ) elButton.setAttribute("data-copylength",cchLength);
+  elButton.onclick = clickCopyButton;
+  /* Make sure the <button> contains a single nested <span>. */
+  if( elButton.childElementCount!=1 || elButton.firstChild.tagName!="SPAN" ){
+    while( elButton.firstChild ) elButton.removeChild(elButton.lastChild);
+    elButton.appendChild(document.createElement("span"));
+  }
+  return elButton;
+}
+setTimeout(function(){
+  var elButtons = document.getElementsByClassName("copy-button");
+  for ( var i=0; i<elButtons.length; i++ ){
+    initCopyButton(elButtons[i],0,0);
+  }
+},1);
+/* The onclick handler for the "Copy Button". */
+function clickCopyButton(e){
+  e.preventDefault();   /* Mandatory for <a> and <button>. */
+  e.stopPropagation();
+  if( this.disabled ) return;   /* This check is probably redundant. */
+  var idTarget = this.getAttribute("data-copytarget");
+  var elTarget = document.getElementById(idTarget);
+  if( elTarget ){
+    var text = this.getAttribute("data-content");
+    if( !text ){
+      text = elTarget.innerText.replace(/^\s+|\s+$/g,"");
+      var cchLength = parseInt(this.getAttribute("data-copylength"));
+      if( !isNaN(cchLength) && cchLength>0 ){
+        text = text.slice(0,cchLength);   /* Assume single-byte chars. */
+      }
+    }
+    copyTextToClipboard(text);
+  }
+}
+/* Create a temporary <textarea> element and copy the contents to clipboard. */
+function copyTextToClipboard(text){
+  if( window.clipboardData && window.clipboardData.setData ){
+    window.clipboardData.setData("Text",text);
+  }else{
+    var elTextarea = document.createElement("textarea");
+    elTextarea.style.position = "fixed";
+    elTextarea.value = text;
+    document.body.appendChild(elTextarea);
+    elTextarea.select();
+    try{
+      document.execCommand("copy");
+    }catch(err){
+    }finally{
+      document.body.removeChild(elTextarea);
+    }
+  }
+}